Apple Scab? What's That?

I believe my apples have been suffering from apple scab. Apple scab is a fungal disease where the leaves on the tree initially have green spots. The lesions get bigger and turn brown and scabby looking. If you look closely and my pic, you'll see what I mean. It embiggens nicely with a click.

I've read that raking under the tree may lessen the problem, as will fungicides. I'll try raking this fall and see what happens.